Do F1 rules permit the discrete usage - of the ~10% ETOH fuel fraction - as ADI?
Is use of 'inert' H2O - as ADI - allowed?
The AFR can be controlled within reasonably close limits by controlling boost with the MGUH.Tommy Cookers wrote:whatever the notional 'best BTE' AFR is ….. there is no true 'best BTE' AFR for the F1 engine as it will not use a fixed AFR throughout even WOT running ? 'best BTE' AFR for 10500 rpm is only maintained above 10500 if cylinder charging is reduced with rpm to keep mass flow constant this means the CR is sub-optimal over 10500
That would be so if the max-fuel-rate was also reduced in line with fuel allowance - which of course would make sense. Regardless, I don't think the best BTE AFR will change much, so a lower boost would be required to maintain AFR with the lower fuel rate. If anything best BTE AFR may get a little leaner due to lower thermal stress and knock tendency. A higher mechanical CR would be an obvious alteration.Tommy Cookers wrote:this problem could be addressed (as I suggested 2 years ago) by raising exhaust pressure relative to induction pressure so reducing crankshaft power and increasing recovered (electrical) power (and increasing overall efficiency)
but the rules limit this by constraining the use of electrical power via the MGU-K power limit so anyway there will surely be different 'best BTE' AFRs for different power envelopes ? (and surely in each race we want to use all the fuel allowed)
and the 'best BTE' AFR will surely change with future reductions in fuel allowance with the current fixed engine size etc and rpm ?
"very near" could mean anything.Tommy Cookers wrote:BTW V Ganesan's book (3rd edition) appears to be available as a free download the Prof's view (on the value of fuel:air cycle predictions of gains from lean running of SI engines) can be read there (chapter 4.7 and eg figure 4.6) he says the best BTE occurs 'within the lean zone very near the stoichiometric ratio'
No.J.A.W. wrote:Do F1 rules permit the discrete usage - of the ~10% ETOH fuel fraction - as ADI?
Is use of 'inert' H2O - as ADI - allowed?
The rules only allow one DI injector per cylinder. I would be surprised if anyone is even using ethanol (unless it is mandated) due to its low energy density. Energy density has priority over octane rating.J.A.W. wrote:Do F1 rules permit the discrete usage - of the ~10% ETOH fuel fraction - as ADI?
Is use of 'inert' H2O - as ADI - allowed?
Impressive!J.A.W. wrote:Is this high efficiency SI - in F1 use?
http://www.federalmogul.com/en-US/Media ... _62013.pdf
There is a minimum biofuel component in the fuel rules. Don't think it is allowed to be used separately.gruntguru wrote:The rules only allow one DI injector per cylinder. I would be surprised if anyone is even using ethanol (unless it is mandated) due to its low energy density. Energy density has priority over octane rating.J.A.W. wrote:Do F1 rules permit the discrete usage - of the ~10% ETOH fuel fraction - as ADI?
Is use of 'inert' H2O - as ADI - allowed?
To confirm:J.A.W. wrote:Do F1 rules permit the discrete usage - of the ~10% ETOH fuel fraction - as ADI?
Is use of 'inert' H2O - as ADI - allowed?
Yes. The minimum octane is 87, defined by (RON + MON)/2.gruntguru wrote:Thanks Wuzak. Is the octane number prescribed? If so I think the brewers would use a higher energy density, lower octane biofuel like bio diesel. The octane can easily be recovered in other ways.
wuzak wrote:To confirm:J.A.W. wrote:Do F1 rules permit the discrete usage - of the ~10% ETOH fuel fraction - as ADI?
Is use of 'inert' H2O - as ADI - allowed?
5.14.2 Other than engine sump breather gases, exhaust gas recirculation, and fuel for the normal purpose of combustion in the engine, the spraying of any substance into the engine intake air is forbidden.
Another rule covers that:J.A.W. wrote:wuzak wrote:To confirm:J.A.W. wrote:Do F1 rules permit the discrete usage - of the ~10% ETOH fuel fraction - as ADI?
Is use of 'inert' H2O - as ADI - allowed?
5.14.2 Other than engine sump breather gases, exhaust gas recirculation, and fuel for the normal purpose of combustion in the engine, the spraying of any substance into the engine intake air is forbidden.
Would this rule imply that a BMW 801 C3-style fuel spray - on top of regular DFI - into the compressor air intake, is allowed?
@ J.A.W .... plasma etc ignition is of course bannedTommy Cookers wrote: JP 9 & 10 (cruise missile fuels) .... are outstanding in volume-specific energy but not in mass-specific energy
can't confirm gasoline sources better than 47 MJ UCV (ERC A 19A)
(bio) Isobutanol can be made into gasoline that fulfills the 5.7% biofuel obligation
IB from coal was used to make gasoline in WW2
BIB is now made 'commercially' as a feedstock for fuel manufacture
credit is due to a fellow poster for first mentioning this biofuel
the permitted lead level seems trivial, boosting Octane No by less than 1 in fuel of conventional composition
but Triptane is legal, and being very sensitive to lead if used as a major constituent it could deliver a gain of about 3 or 4 Octane nos